Crustaceans

Northern Rock Barnacle (Balanus balanus) - Large conical barnacle has a rough surface. Sides have 2 pairs of plates that overlap 1 of 2 unpaired plates (6 plates total). Color: grayish white. Size 2" (height in width). Found on rocks, subtidally to 500'. Will compare to invasive "Down under" Barnacle. This specie has 4 plates. Size up to 1".

Baltic Isopod (Idotea baltica) - Bug-like creature which is very common. The body is broad, ovate and somewhat flat. There are 7 thoracic segments, each with a pair of similar legs. Eyes are large and on the side of the head. Color: variable, often mottled - dark green, reddish, brownish, or tannish in many patterns. Size 1" long, ¼"wide. Found in shallow water on the bottom on rocks, or algae.

Red Opossum Shrimp (Heteromysis formosa) - Small shrimp that is slender. 1st pair of antennae with 1 short and 1 long slender branch; 2nd pair with 1 long, slender branch and 1 flattened, broad, oval leaf-like branch. Color, red, pink, or brownish. Size, 3/8". Found in tidepools, under rocks and hiding in shells from above low-tide line to 800'.

Sand Shrimp (Crangon septemspinosa) - This shrimp resembles sand walking along the bottom, a perfect example of camouflage. Look closely on sand bottoms for 2 very small black dots moving along the bottom - you will see a shrimp following closely behind. Color is almost translucent to opaque with greenish tint, mottled with brown or black (the color of sand). Size to 3". Found on sandy bottoms and ell grass, from tide pools to shallow water.

Bent Opossum Shrimp (Praunus flexuosus) - 1" long shrimp that is slender, tannish, with branching, blackish spots. Eyes large, stalked, golden with black centers. Abdomen is long, slender, with slight S-shaped bend. 5 pairs of forked, bristly abdominal appendages, last one flattened. Found among seaweeds and rocks in shallow water. An introduced specie from Europe, first discovered in 1960 on Cape Cod, now widely distributed through Gulf of Maine.

Montague's Shrimp (Pandalus montagui) - Shrimp has a smooth carapace. It lacks a middle spine on the abdomen. The 2nd right walking leg has 20 segments. Color; pink to red, or red stripes in juveniles. Size to 5". Edible, is also known as Northern Boreal Shrimp. Found subtidally to open ocean.

Acadian Hermit Crab (Pagurus acadianus) - Most common hermit crab in New England. The 1st pair of legs have pincers with an orange stripe down the middle and are covered with tubercles. The right leg is much bigger. Color; carapace - brown,; legs - red/orange to brown,white at the base, 1st pair of antennae & eye stalks-blue; eyes-yellow. Size; carapace 1 ¼", width 1". Found on gravel, or rock bottom to 1600'.

Northern Lobster (Homarus americanus) - This critter needs no introduction. Most people refer to this "bug" as their dinner. Member of the insect family, the northern lobster is easy to identify. 2 large claws - one cutting claw and a larger crushing claw. Swims backwards with quick pulses of the tail. Color: greenish brown or orangish, but may be blue, white, or red. Size t o 4' in length. Found in all habitat types from shallow water to 2000'.

Rock Crab (Cancer borealis) - The carapace is broad, convex and inundated with fine granulations. The forward border of the shell has 9 rounded, successively-pointed teeth with granulated edges. Carapace color - yellowish with many brick red to purple red, or purplish brown dots. Size to 5" wide. Found on rocky shores, intertidally to 2600'.

Jonah Crab (Cancer borealis) - The carapace is oval shaped and its surface is finely granular. There are 3 low teeth between the eyes and 9 wide teeth with deep, indented margins on each side of the eye sockets. Carapace color - brick red, ventral surface - yellowish. Size 6" wide. Found in rocky shores and bottoms, intertidally to 2600'.

Green Crab (Carcinus maenas) - An introduced specie that most likely came over in bilge water from Europe. The carapace is fan shaped. Frequently found in tide pools, this crab is easily attracted to dead fish or crushed shellfish. Carapace color - males, green, females - orange red ventrally. Size to 3". Found among rocks, intertidally to shallow water.

Asian Shore Crab (Hemigrapsus sanguineus) - Pretty small crab. Banded legs, red spots on claws, variable colors; square shape; Size up to 1". Prefers rocks, cobble. Intertidal to subtidal in winter.